Sources of Resistance to Rough Leaf Spot Disease in Sweet Sorghum. Natale Zummo, Research Plant Pathologist, USDA, ARS, Crop Science Research Laboratory, Mississippi State University, Mississippi State 39762. D. M. Broadhead, Research Agronomist, U.S. Sugar Crops Field Station, Southern Region, USDA, ARS, Rt. 13, Box 14, Meridian, MS 39301. Plant Dis. 68:1048-1049. Accepted for publication 10 May 1984. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1984. DOI: 10.1094/PD-68-1048.

Of the 403 exotic and 631 commercial, unreleased, and parental sweet sorghum lines field-tested for resistance to rough leaf spot disease at Meridian, MS, only two lines (MN 3344 and MN 4055) showed a high level of resistance in 1981 and 1982. MN 4055 remained completely free of the disease. MN 3344, which was introduced from India as PI 201754, showed only slight infection. No other lines showed good resistance to the disease. With a projected increase in grain sorghum production in Mississippi, the identification of sources of resistance to rough leaf spot disease in sweet sorghum will be of value to the grain sorghum industry.